Denim and other material garments have often been processed to make them look worn. Consumers have shown a desire to purchase broken-in garments.
Currently available techniques of processing such garments include mechanical sandblasting with sand or other abrasive; hand, mechanical, or robotic rubbing, and others. The effects may include local abrasion which is a wear pattern from below the waist to below the knee section. Another effect is global abrasion, which describes a wear pattern from below the waist to the cuff. xe2x80x9cWhiskersxe2x80x9d are a term which describes the wear that occurs along the creases and hem of the article during wear. Yet another worn look is a rectangular area marked on the rear pocket of the jean, which simulates the worn look caused from carrying a wallet in the back pocket. Yet another worn look is referred to as xe2x80x9cfrayedxe2x80x9d, where the degree of wear is so severe that the individual threads of the cotton fiber are exposed. Such a pattern section may even have holes in the denim fabric.
The sandblasting process for local and global abrasion may use sandblasting equipment to abrade the denim jeans with sand particles or other abrasive media. This process blasts sand particles from a sandblasting device to a pair of jeans. The random spatial distribution of the sand creates a special appearance in a treated area that is referred to as xe2x80x9cfeatheredxe2x80x9d. The abrasion in the feathered area varies from light along the perimeter of the pattern, e.g., the edges and top of the pattern, to heavy in the center of the pattern. This unique appearance may simulate the look of denim jeans that have been worn for a considerable time.
However, the sandblast process has a number of problems and limitations. For example, the process of blasting sand or other abrasive media presents environmental and health issues. Typically, a worker needs to wear protective gear and masks to reduce the impact of inhaling airborne sand. The job is considered to be a hazardous job, and may cause high employee turnover.
The individual skill of the operator may also be critical in reducing the scrap rate associated with the sandblast process. This has the additional effect of increasing certain costs of labor for the sandblast operator which are typically higher than the labor rate for other employees in the denim finishing plant, since their skill may be important. The actual blasting process may occur in a room which is shielded from other areas in the manufacturing facility.
Further environmental issues arise with the cleanup and disposal of the sand.
The sandblasting process is an abrasive process, which causes wear to the sandblasting equipment. Often, the equipment needs to be replaced on a yearly basis or even more frequently. This, of course, can result in added capital, maintenance and installation expense.
Also, new designs such as shadow effects along the top or bottom of the whisker are difficult to impossible to obtain with the conventional sandblasting processes.
All in all, the sandblasting process may cost in excess of $1.00 per pair of jeans, due to the cost of labor, materials, and scrap produced, and environmental clean up required. It is difficult to duplicate the exact placement of the sandblast pattern from one garment to the next due to the variability of the process itself and the variability from one laborer to another.
The sandblast process can also adversely affect the tear and tensile properties of the denim jeans due to the abrasion of the sand on the denim. It is not uncommon for the sandblast process to reduce the tear and tensile strength of the denim by as much as 50%. Further, the tear and tensile strength variation following sandblasting is high due to the uncontrollability of the abrasive process. Some manufacturers even need to test the tear and tensile properties of the denim at specific locations where the abrasion is the least to even pass the apparel company standards for tear and tensile strength.
Other approaches to creating worn looks present their own problems. In the case of whiskers or frayed looks, manufacturers may rely upon very labor intensive, expensive and slow hand rubbing or sanding processes where the whiskers or frayed looks are applied to the denim by hand sanding, sometimes with a rotating drill such as a DREMEL(trademark) tool. In addition to the labor costs associated with such a process, this hand sanding operation is often associated with defects after washing, where the sanding of the individual whiskers on the denim may be too little or too much resulting in a low quality product. Some manufacturers have even tried to use robotic sanding processes to avoid these problems, albeit at considerable capital investment and limited flexibility.
Despite the above shortcomings, sandblasting and rubbing processes remain in wide use because the market desires worn look denim.
The present assignee has disclosed laser processing of denim, e.g. in U.S. Pat. Nos. 5,990,444; 6,002,099 and 5,916,961. These techniques enable using a laser to change the look of a textile product.
In recognition of the above, the inventors propose new laser scribing devices and techniques to simulate specified worn looks on fabrics and garments.
One aspect includes using a laser to scribe lines on a garment, where the energy density per unit time of the laser causes the garment to change color to varying degrees from indigo blue or black to white or grey. Both the individual scanned lines and different sections of a lazed pattern can have washing, where the sanding of the individual whiskers on the denim may be too little or too much resulting in a low quality product. Some manufacturers have even tried to use robotic sanding processes to avoid these problems, albeit at considerable capital investment and limited flexibility.
Despite the above shortcomings, sandblasting and rubbing processes remain in wide use because the market desires worn look denim.
The present assignee has disclosed laser processing of denim, e.g. in U.S. Pat. Nos. 5,990,444; 6,002,099 and 5,916,961. These techniques enable using a laser to change the look of a textile product.
In recognition of the above, the inventors propose new laser scribing devices and techniques to simulate specified worn looks on fabrics and garments.
One aspect includes using a laser to scribe lines on a garment, where the energy density per unit time of the laser causes the garment to change color to varying degrees from indigo blue or black to white or grey. Both the individual scanned lines and different sections of a lazed pattern can have varied energy density per unit time. The variation in energy density per unit time can be controlled by changing the power, speed, distance, or duty cycle of the laser as the lines are scribed on the material.
Other aspects are also disclosed.